Hong, J Yoon, DS Kim, SK Kim, TS Kim, S Pak, EY No, K 2024-01-21T05:40:18Z 2024-01-21T05:40:18Z 2021-09-05 2005-01 1473-0197 https://pubs.kist.re.kr/handle/201004/136861 Glass-based microchannel chips were fabricated using photolithographic technology, and Pt thin-film microelectrodes, as coplanar impedance sensors, were integrated on them. Longitudinal design parameters, such as interelectrode spacing and electrode width, of coplanar impedance sensors were changed to determine AC frequency characteristics as design parameters. Through developing total impedance equations and modeling equivalent circuits, the dominant components in each frequency region were illustrated for coplanar impedance sensors and the measured results were compared with fitted values. As the ionic concentration increased, the value of the frequency-independent region decreased and cut-off frequencies increased. As the interelectrode spacing increased, cut-off frequencies decreased and total impedance increased. However, the width of each frequency-independent region was similar. As the electrode area increased, f(low) decreased but f(high) was fixed. We think that the decrease in R-Sol dominated over the influence of other components, which resulted in heightening f(low) and f(hig)h. The interelectrode spacing is a more significant parameter than the electrode area in the frequency characteristics of coplanar sensors. The deviation of experimentally obtained results from theoretically predicted values may result from the fringing effect of coplanar electrode structure and parasitic capacitance due to dielectric substrates. We suggest the guidelines of dominant components for sensing as design parameters. English ROYAL SOC CHEMISTRY CONTACTLESS CONDUCTIVITY DETECTION DOUBLE-LAYER CAPACITANCE ROUGH METAL-SURFACE CAPILLARY-ELECTROPHORESIS ANALYSIS SYSTEMS ELECTRODES DEVICES OPTIMIZATION GLASS SEPARATIONS AC frequency characteristics of coplanar impedance sensors as design parameters Article 10.1039/b410325d 1 LAB ON A CHIP, v.5, no.3, pp.270 - 279 LAB ON A CHIP 5 3 270 279 scie scopus 000227186500005 2-s2.0-16244407397 Biochemical Research Methods Chemistry, Multidisciplinary Chemistry, Analytical Nanoscience & Nanotechnology Instruments & Instrumentation Biochemistry & Molecular Biology Chemistry Science & Technology - Other Topics Instruments & Instrumentation Article CONTACTLESS CONDUCTIVITY DETECTION DOUBLE-LAYER CAPACITANCE ROUGH METAL-SURFACE CAPILLARY-ELECTROPHORESIS ANALYSIS SYSTEMS ELECTRODES DEVICES OPTIMIZATION GLASS SEPARATIONS impedance sensor fequency